And it’s an unexpectedly uplifting morality play that toys with shock film cliches but ultimately transcends them.

Liam Gavin’s film opens in a long-unoccupied manor house in Wales. Sophia Howard (Walker) is being shown the place by a realtor. Apparently she has very specific requirements as to the remoteness of the property and the number of rooms. She agrees to lease the place for a year.

She’s then visited by Solomon (Oram), a balding, bearded, pudgy occultist with whom she’s been in contact. Gradually the nature of what they’re up to becomes clear.

Sophia wants Solomon to lead her through an elaborate ritual that will result in the appearance of her guardian angel. This exercise may take half a year, during which time Sophia must follow Solomon’s instructions to the letter. She’s already abstained from sex and alcohol for several months. She’s purchased weeks’ worth of food. Once the ritual begins neither can leave the premises without dire consequences.

Now this may seem like so much fantastic b.s., but Gavin and his players are so good at establishing their characters and setting a slowly tightening mood of suspense and dread that an audience can’t help but buy into it.

Steve Oram

Walker’s Sophia is clearly a desperate, driven woman, and the reasons slowly become clear. Her young son was murdered several years before in a case that was never solved. Now she hopes the ritual will allow her to communicate with her dead child. She has another motive that she doesn’t initially share with Solomon…she wants revenge on the boy’s murderers.

Solomon, meanwhile, is an owlish nerd, likely alcoholic, who talks so matter of factly about the supernatural events with which he’s been involved that you figure he’s either totally nuts or totally legit.

For much of the film not all that much happens. Rituals are performed without variation. Candles are lit. Runes and geometric forms are chalked onto the wooden floors.

It’s about as exciting as learning the multiplication tables through rote memory. Sophia is tempted to bail, but Solomon warns that now that the ritual is underway, there’s no bowing out.

Little by little, there are signs that the magic is working. A dog howls where there should be no animals. Bits of gold flake rain down like snow from a solid ceiling. Objects don’t stay where they are placed.

Ultimately “A Dark Song” takes its characters right up to the very edge of madness before delivering a final twist that is as gratifying as it is unexpected. Hard-core splatter fans may be disappointed with Gavin’s preference of inference over in-your-face, but this is the rare film that seduces even as it scares.